United Airlines has confirmed plans to reconfigure several of its Boeing 777 airliners to accommodate 10 seats across each row instead of nine in its economy class on domestic routes.

United will retrofit 19 of its 74 Boeing 777 widebodies with the additional seating, applying the change to nine of the aircraft already used for domestic routes, mostly to and from Hawaii.

The 10 other Boeing 777s that will feature the 10-across seat configuration will be shifted from the airline's long-haul international flights, according to Today in the Sky.

United Airlines has confirmed plans to reconfigure several of its Boeing 777 airliners to accommodate 10 seats across each row (bottom) instead of nine (top) in its economy class on domestic routes

United will retrofit 19 of its 74 Boeing 777 widebodies (one picured above) with the additional seating, applying the change to nine of the aircraft already used for domestic routes, mostly to and from Hawaii

With the update, the economy-class layout will feature 10-abreast seating in a three-four-three seat configuration compared to its current two-five-two and three-three-three seat configuration.

The layout will reportedly mean a reduction in elbow room as seat width decreases from 18 inches to 17 inches, but leg room should not be affected

The update will increase the capacity of seats on the 19 777s set to be retrofitted to 364, including 28 in business class and 336 in coach, according to Today in the Sky.

There will also be some additions as part of the design such as in-seat power outlets throughout the cabin, mobile device holders for tables and phones and the aircraft will be Wi-Fi enabled.

The Chicago-based carrier plans to begin the retrofitting in May and have it completed by 2017.

United's 777 fleet that stay on international routes will continue to have the nine-across seat configuration in coach, with a total of up to 269 seats.